What's This? White Tube Growths On Lr?

[jaffacake]

Over the past 2 weeks i've had a really bad increase in hair algae on some LR in my tank only on one side, I will be getting some more inverts inc some emerald crabs to help with this problem but a few days ago i noticed a new problem. I have these white little things growing all over my live rock, they seem to be tucked into small areas and some have little things coming off them like tenticles, i'm completely lost. My water stats are the same as always.
Can someone identify what this is from the photos and how to remove?

 

[VictorMeldrew]

I have some of them in my tank, they do not seem to be causing any problems but I do not have to many, I thought they might be some kind of aiptasia, not really sure.

 

[kj23502]

pine apple sponges man Good things

Mine have disappeared since adding my angel...as well as my fan worm hitchhikers...disappeared to.

 

[jaffacake]

I've just done a search on pineapple sponges and the pictures match exactly what's in my tank.
So they're good things? What do they do and how big do they grow/multiply?

 

[kj23502]

I don't know how they multiply but they feed off stuff in the water. They aren't bad and could come and go, also increase or decrease.

 

[-Nemo-]

Tunicates would be my guess.
Harmless filter feeders

 

[kj23502]

They are NOT tunicates.

 

[seffieuk]

Yep agree with KJ, pinapple sponges, harmless filter feeders

Seffie x

 

[jtnova13]

have a bunch in my tank too